<style type="text/css">
.aaa {
	border: 1px hidden #0000FF;
	width: 100px;
	height: 60px;
	background-color: #cccccc;
}
</style>
<input id="bigclassauthorize" type="checkbox" onclick="bigChange(this)" />
大类
<div class="aaa">
	<input type="checkbox" id="1" onclick="smallChange(this)" value="小类一" />小类一<br />
	<input type="checkbox" id="2" onclick="smallChange(this)" value="小类二" />小类二<br />
	<input type="checkbox" id="3" onclick="smallChange(this)" value="小类三" />小类三
</div>

<script language="javascript" type="text/javascript">
	
	function smallChange(obj){
		if(obj.checked == true){
			alert(obj.id+"xianshi");
		} else{
			alert(obj.id+"yincang");
		}
		
		
	}
	
	
	
   /*
    function bigChange(obj) {
        if (obj.checked == false) {
            var smObj = document.getElementsByName("smallclassauthorize");
            for (var i = 0; i < smObj.length; i++)
                smObj[i].checked = false;
        }
    }
    function smallChange(obj) {
        var smObj = document.getElementsByName("smallclassauthorize");
        var bigObj = document.getElementById("bigclassauthorize");
        if (obj.checked == true)
            bigObj.checked = true;
        else {
            b = true;
            for (var i = 0; i < smObj.length; i++) {
                if (smObj[i].checked == true)
                    b = false;
            }
            if (b == true)
                bigObj.checked = false;

        }
    }
    */
	
	
</script>